Light showers pattered into the Los Angeles Basin on Monday, but they were about all the rain Southern California got from a cold front that moved across the northern and central parts of the state.

At mid-evening, the National Weather Service observed that rain was falling over much of the basin, the San Gabriel Mountains and the Antelope Valley, "but this precipitation was too light to be detected by radar."

The Southland mountain areas had light rain or snow above 7,000 feet during the night with gusty west to southwest winds of 20 to 35 m.p.h. Snow accumulations were expected to be light, generally less than four inches, forecasters said.

The front also dumped snow in the Sierra Nevada.

By late afternoon, .03 of an inch had been measured at the Los Angeles Civic Center, bringing the season total to .27.

Mt. Wilson reported .79 by that time, Santa Monica had .18, Long Beach had .02, Monrovia and Pasadena had .06, Santa Barbara had .48, Santa Maria had .37 while San Bernardino and San Gabriel reported .03.

The National Weather Service said occasional light rain during the evening would give way to partly cloudy weather today with downtown highs in the low 70s. A warming trend was seen for Wednesday with mostly clear skies.

Monday's downtown high was 68 degrees after an overnight low of 63. The high relative humidity ranged from 75% to 55%.

Rain and wind produced some of the usual problems in the Los Angeles area, including skidding-traffic accidents and scattered power outages. A Los Angeles Department of Water and Power spokesman said about 2,400 customers in the Highland Park, Hollywood and Westwood areas were without power just after 3 p.m.

A short time later, lights began going out in South-Central Los Angeles. An estimated 2,600 around the city were powerless when darkness fell, the spokesman said.

To the north, the storm system dropped about two-thirds of an inch of rain in parts of the San Joaquin Valley.

The first major storm of the season--which normally is expected sometime in November--drenched the San Francisco Bay Area before swinging inland to drop heavy snow in the Tahoe Basin and prompt warnings to travelers there. The warnings were canceled, however, as the storm moved eastward out of the state.

Up to eight inches of snow fell at Lake Tahoe. Winds were blowing at 30 to 40 m.p.h. with some gusts up to 50 m.p.h. in that area. Winds had been clocked at more than 80 m.p.h. late Sunday night in northern Nevada, where there were numerous power outages.

Some Routes Closed

Caltrans closed several state highways leading into the central and southern Sierra Nevada, but a spokesman said the passes might be reopened before the customary winter closing, unless there is "a series of major storms."

These were California 4 at Ebbetts Pass, California 89 at Monitor Pass, California 108 at Sonora Pass and California 120 at Tioga Pass.

The snow level was down to about 3,600 feet and accumulation was about 16 inches at the 9,000- to 10,000-foot levels, said Ken Gosting of the Tuolumne County Visitors Bureau. He said half a dozen expert horsemen set out to search for several backpackers believed caught in the sudden snowstorm somewhere in the Emigrant Basin Wilderness Area.

In the Tuolumne County community of Twain Harte, the heavy snow gathered on trees still full of foliage and then fell in heavy clumps to down wires, leaving a wide area without power. A brand new FM radio station, KKBN, went on the air for its first full day--only to to be knocked off the air by the blackout.